Patent GB-706778-A (GB)
Title: Improvements in or relating to apparatus for selectively printing on electrosensitive record material
IPC: B28B21/98
Filed: 1951-02-26
Abstract: 706,778. Typewriters &c. NATIONAL CASH REGISTER CO. Feb. 26, 1951 [March 3, 1950], No. 4584/51. Classes 100 (2) and 100 (4) Machine with inkless printing; matrix carriages.-A selective printing apparatus for printing on an electrosensitive record strip 20 by passing an electric current through it, comprises a rotating cylinder 23 carrying a row of matrices each comprising number of electrode elements, the matrices being brought successively to a printing position where the current passes through the record to a co-operating electrode at the other side of the strip. The electrode elements forming the matrices comprise strips 30-36 and according to the character to be printed are selectively applied with a potential 77, Fig. 6, through contacts 90 (which open if the supply of record strip is exhausted), print contacts 80, the various contacts of the operating keys 1-9 and 0, current limiting resistors 78, brushes 61, and commutator rings 52-58. As the strips 30-36 pass the co-operating electrode, shown in the form of a spring brush 24, the electric current flows through the strip and in the usual type of electrosensitive record strip forms a black image on a greyishwhite background. The electrodes 30-36 are mounted on a rotating cylinder 23, Fig. 3, which comprises six groups of seven commutator rings 52-58 for each group of electrodes for printing in six columns on the record strip or alternatively in letter-space sequence in one or more lines on a tape. The electrodes 30-36 are repeated radially around the cylinder so that they may, one after the other come opposite the co-operating electrode 24. The commutator rings are insulated from each other and are bolted on to a plate 41 rotatably mounted on a sleeve 45 which is secured to a supporting plate 22 by a nut 47 and member 48. The sleeve 45 has a flange 56 carrying four mounting brackets 62, 63, 64 and 65 (not shown) supporting contact brushes 61 which engage the commutator rings 52-58, the brushes 61 being arranged so that those engaging adjacent rings are mounted on different brackets 62-65. Letter and line spacing.-The cylinder 23 and plate 41 are rotated by a gear 44 from a gear on a shaft 85, Fig. 6, rotated by a ratchet-wheel 84 advanced by a pawl 83 each time a magnet 81 is energized from a print key 96 and battery 95. To ensure that a complete step of the ratchet takes place contacts 99 close on a small movement of the ratchet-wheel 84 operating a relay 98 having contacts 97 bridging the print key 96 until the ratchet-wheel 84 has completed one step, whereupon, and only then, is the contact 99 allowed to open. The gear 44 is also arranged to drive a feed roller 25, Fig. 1, and a matrix cleaning brush 105 adjacent to which is a suction duct 110. If required the cylinder and feed rollers may rotate continuously, printing taking place as the record strip travels through the apparatus. Multiple web arrangements.-Two superimposed records may be fed over electrodes 30-36 and 24 shown causing simultaneous printing at the one printing position shown, or alternatively at separate points around the cylinder 23, where a second electrode 24 is positioned.